import binandint
def alu(a,b,alu_ctrl):              #a,b为两个运算数，alu_ctrl为控制信号，返回运算结果result与是否为0 zero
    if alu_ctrl=='00000':
        pass
    elif alu_ctrl=='00001':
        pass
    elif alu_ctrl=='00010':
        pass
    elif alu_ctrl=='00011':
        pass
    elif alu_ctrl=='00100':
        pass
    elif alu_ctrl=='00101':
        pass
    elif alu_ctrl=='00110':
        pass
    elif alu_ctrl=='00111':
        pass
    elif alu_ctrl=='01000':
        pass
    elif alu_ctrl=='01001':
        pass
    elif alu_ctrl=='01010':
        pass
    elif alu_ctrl=='01011':
        pass
    elif alu_ctrl=='01100':
        pass
    elif alu_ctrl=='01101':
        pass
    elif alu_ctrl=='01110':
        pass
    elif alu_ctrl=='01111':
        pass
    else:
        pass